The present invention relates to a coaxial repeater and, particularly, to a connector structure of a repeater portion for relaying an external signal input through a coaxial cable in a CATV (Cable Television) system to an internal electronic device.
In the CATV system, an input/output portion of a device using a coaxial cable usually has a structure in which a signal input from an external connection adapter called FT (Field Through) adapter fixed to a casing of the device is output from a connector or a block provided on a PWB (Printed Writing Board) through the PWB to an electronic device (amplifier portion) inside the device.
Such structure of the input/output portion may be realized by transmitting a signal by fitting or soldering a center conductor of an adapter mounted on the casing to a connecting metal hardware mounted on a printed circuit board, as to be described later. Alternatively, the structure may be realized by passing a center conductor of an adapter mounted on the casing through a connecting block mounted on a printed circuit board and connecting the center conductor to the block by vertically pressing the block to the center conductor by screws.
Japanese Utility Model Application Laid-open Nos. H5-81955 and H5-85095 and Japanese Patent Application Laid-open No. H9-17521 disclose other structures than those mentioned above.
When the above mentioned conventional connecting structure of the input/output portion, in which the center conductor of the adapter is fixed to the block by the screws or connected in point contact to the block by the connecting metal hardware of such as resilient material, is used in a CATV coaxial repeater operable in a high frequency range (not lower than 450 MHz), it becomes difficult to maintain electric characteristics (grounding characteristics, return loss and undesired radiation, etc.) due to small contact portion and, therefore, a special consideration (for example, a provision of a shield plate and/or a spring for making the grounding reliable) for maintaining the electrical characteristics is required, which causes an assembling to be complicated and a cost to be increased.
When the center conductor of the adapter is connected to the block or the connector and then to the internal electronic device through the printed circuit board, the signal is transmitted to the electronic device through a plurality of connecting portions. Therefore, there may be a signal loss (return loss, grounding potential) between the connecting portions. In such case, the signal flowing between the printed boards is influenced by undesired radiation produced within the device and noise may be introduced to the signal, leading to a degradation of the electrical characteristics of the device.